Melting point apparatus



Nov. 10, 1953 Filed Oct. 29, 1948 J. VANDERKAMP 2,658,382

MELTING POINT APPARATUS 2 Sheets-Sheet l F I d n-i John UZmderKanzp Unverzbor b i?:}a 4/ Gbbckn Nov. 10, 1953- J. VANDERKAMP 2,658,382

MELTING POINT APPARATUS Filed 001;. 29, 19-48 2 Sheets-Sheet 2 FIGx' z FIG.-3

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John. Uanderkamp {inventor bfig 2% Cltborrzes l alented Nov. 10, 1953 UNITED STATES PATENT OFFICE MELTING POINT APPARATUS John Vanderkamp, West Orange, N. J.

Application October 29, 1948, Serial N 0. 57,180

Claims.

This invention deals with a melting point apparatus employed for determining the melting points of solid materials.

The invention may be more readily understood by reference to the drawings: in which a preferred embodiment. is illustrated. Figure 1 shows a side view in cross section of the complete unit. Figure 2 is a view of the upper portion of the unit, looking down into heating chamber [5 with cover 25 removed, while Figure 3 depicts a bottom view of cover 25 to which the heat-capacity member 20 is. attached. In Figure 4 is shown a top view, and Figure 5 a side view, of the metal thermometer and sample holder which fits into cover 25. A side view of the upper portion of the entire unit (shown in Figure 1) is illustrated with magnifier attached, in Figure 6. Similar numerals refer to similar parts in the various figures.

Referring again to the drawings, numeral 1 represents the top, 2' the bottom and 3 the side of a circular hollow base, in the center of the top I of which is mounted hollow stand 4 attached to top i by screws 35. Stand 4 may be of any length, but is preferably about 9" long, and is mounted on the top to base 8 of hollow cylindrical housing it by means of collar 5 and screws 6, 1, etc. This housing holds a light source, such as bulb 9 which preferably rests on the sides of the hole in base 8. Cylinder Ill is attached to base 8 by screws I l, and is preferably lined inside with insulating material,

On top of cylinder 10 is firmly mounted cover plate l2 made of insulating material such as hard asbestos board, and having a centrally disposed circular hole cut therein. Firmly mounted on plate I2 is base E3 of the heating chamber. Base I3 also is provided with a centrally disposed circular hole in juxtaposition with the one in plate l2 and in which is cemented frosted glass window M for transmitting light from bulb 9 into the heating chamber.

The heating chamber comprises cylindrical metal walls l5 and I5 (see Fig. 2) between which is packed an insulating material it, such as asbestos fibers, magnesia, and like. Projecting from base l3 are rod electrical heating elements 18, three of which are shown in the design of the present example. An open window 24 is provided through wall -45 to allow visibility into the heating chamber from the outside. A cylindrical outer cover I! of transparent glass is provided over wall [5' to act as further insulation as well as to prevent convection currents through window 24.

The cover shown in. Figure 3 fits into and over the heating chamber. The heat-capacity mass 20 is a cylindrical mass of solid copper, aluminum, or other heat conducting material fitting inside wall 15 and having holes 22 slightly larger in diameter than heating elements is, thereby enabling slipping thereover as a tight fit. An open window 24 is also drilled into the side of cylinder 20 so that it may be placed in juxtaposition with window 24 of wall |5'-l.5 to enable the viewing from the outside of the melting of the crystals in centrally disposed space 23. Shoulder 2lis provided on cylinder 26 to enable resting of said cylinder inside the heating chamber with its bottom near base 13 of the heating chamber. Cover plate 25 attached to the top of cylinder 20 is preferably of insulating material such as hard asbestos board, and is provided with centrally disposed hole 23 into which is inserted thermometer and sample holder 19.

Holder i9 is also of high heat conducting material such as copper, aluminum, etc. and comprises cap portionv H which rests on top of plate 25, and body portion 31 which is inserted inside central hole 23 of cylinder 20. The length of body portion 31 is preferably the distance from the top of cap 25 to the upper edge of window 24 so as to enable the samples of crystals 3'! (the melting point of which is to be determined) contained in sample tubes 38, 39, etc., the upper ends 2i of which are slightly Wider, to project into the field of vision in window 24. It will be observed that body 3| of holder 19 has large hole 30 for housing a thermometer 26 and smaller holes 28 in which are inserted melting point tubes 2! (of glass) in which the crystals, etc. 3? are inserted for melting. Thermometer 26 may rest on window l4 without appreciably affecting the reading thereof.

In order to facilitate accurate timing of the melting of crystals 31, a magnifier "it is mounted in front of window 24 (Fig. 6) on stand 29 on which the magnifier slides by means of friction sliding holder 28 to which it is attached.

Wires 33 for the electrical circuit of bulb 3 are introduced into hollow base i through side 3, and switch 35 is mounted on the top of the base for turning on the current for the bulb. Wires 3 t for the rod heaters l8 are also introduced into base side 3 and led through hollow stand 4 to feed current to the heaters. The wires 34 are led to a variable transformer or rheostat by means of which the amount of heat delivered in the heating chamber is controlled.

\ Among the advantages of the present apparatus aeraese is the upward lighting through window 14 which eliminates glare from the thermometer bulb. The latter appears black and thus does not tire the eyes of the operator. Also, the unit may be cooled rapidly by removing cylinder 20 and immersing it in cold water, thereby enabling the running of as bulb on a rod inside stand d. Also, it is possible i to have any number of heating elements, as desired, or cylindrical coil mounted adjacent wall 15 may be employed, although this is not as satisfactory as the rod heaters since the heating up period is longer with such heating means. The stand shown may not be necessary in some cases, as When the upper portion is mounted on a laboratory stand or other support.

Although the bottom source of illumination for the chamber is preferred, it is within the purview of this invention to include other types of illumination, as for example, a ray of light directed angularly from the outside of the chamher through window 24.

I claim:

1. In a melting point apparatus, an insulated covered chamber, said chamber having means forming a window in the side, a transparent cover for said window, a mass of solid of high heat conductivity snugly fitting into said chamber, there being a vertical centrally disposed opening extending through said solid to receive the sample to be melted, there being means forming a hole in the side of said mass in registry with the window in the chamber to allow view therein from the outside and in communication with said vertically disposed opening, the lower face of said mass having a plurality of means forming vertically extending holes, heating rods disposed within said last mentioned holes, and illuminating means beneath the bottom of said vertical opening in said mass for illuminating the sample.

2. A melting point apparatus according to claim 1 in which the illumination means comprises means forming a window in the bottom of the chamber, and a light disposed thereunder.

3. A melting point apparatus according to claim 1 in which a removable metal holder is disposed to fit closely into the top of said centrally disposed opening, said holder being short enough to enable the sample holder to project from the bottom thereof in clear view within said window.

4. A melting point apparatus according to claim 1 in which the chamber is cylindrical in shape and the transparent cover for said window is a hollow glass cylinder fitting closely around the outside of said chamber.

5. A melting point apparatus according to claim 1 having a second chamber disposed under the chamber containing said mass, and the illumination means comprises a light-transmitting window forming at least a portion of the upper wall of said second chamber, immediately below said vertical opening in said mass, and a light source disposed within said second chamber.

JOHN VANDERKAMP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,362,368 Talley Dec. 14, 1920 1,652,200 Hanson Dec. 13, 1927 2,036,432 Musante et a1. Apr. '7, 1936 2,162,614 Fry et a1. June 13, 1939 2,467,129 Huber Apr. 12, 1949 

